|
Hi Bill;
When I first
looked at my wastegate I was shocked at how small it was. I remembered Rusty
previously commenting on this as well, as he had mentioned discussion of it on
the RX-7 forum. /so I joined the forum at www.rx7club.com/forum/ to gain access
to the archives. There I found alot of info on the problem of boost creep on the
earlier turbochargers.
I used some toolmakers ink (paint would work just as
well) to spray on the closed wastegate, then opened it and the outline of the
gate was clear. I then used a die grinder to open up to within 1/32 of this
line. I also ported the inside of this passage to open up as large as possible
and provide a smoother flow path.
Control is something I am dealing with now. I've
bought 2 books on turbocharging, which I'm currently reading before making any
decisions. I'm just finishing the first book - "Turbochargers" by Hugh MacInnes.
It was well recomended, however while it is enlightning, it is also raising more
questions than it answers. It is also dated back to 1984 so it isn't exactly
current info. Second book I've yet to get into is "Maximum Boost" by Corky
Bell. It is dated 1997, so is much more current and at a glance seems much more
detailed.
Currently my thinking is to go with an absolute pressure
actuator with a 15 psi spring, for wastegate control to SL. However an initial
Google search has not turned up a source. I really want to limit my boost
to normalization only, as the RV-9 doesn't require any additional ponys, but as
I choose the "9" for mountain flying on short strips, I want to ensure that it
gets all the ponys that it's rated for working at all
times.
When I know more I will post it.
Been real busy latly, but I'd better get at it if want to claim first
rotary RV-9 to fly as I see that Bernie Kerr is getting close as
well.
|